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Saulius I.
1st February 2009, 04:10
1. Please advise, what original parts of 1911 fit to PARA LDA 18.9?
2. I'd like to order a custom made from EGW, but can not idenify what are original dimensions of the Para LDA barrel bushing?
English's not my mother tongue and imperial dimentions is not my strong side:)
I've tried to measure sizes with metric caliper and convert it, but I have faced differences of numbers after comma.
I have know clue if it has so called angle or straight bore, what dimention: .575 .578 .580 .581?
Flange Type? - .092 or .125?
Inside diameter of the slide - usually .699 - .705 ?
Outside diameter of the barrel - usually .575 - .583 ?
Any help would be mostly appreciated. Thanks a lot.
Regards,
S.

Hawkmoon
1st February 2009, 08:53
1 English inch = 25.4 mm

The standard 1911 parts are:

Barrel bushing
Recoil spring plug
Recoil spring (for a 9mm, of course)
Recoil spring guide (either standard or full-length)
Hammer (and hammer pin)
Hammer strut (and strut pin)
Sear (and sear pin)
Disconnector
Mainspring and related parts
Sear spring
Firing pin and firing pin stop (Series 80 style)
Firing pin spring
Ejector
Plungers and plunger spring (the plunger tube is integral to the frame)
Thumb safety
Grip Safety
Slide Stop

Para does not use a thick flange on the barrel bushing. A standard barrel bushing flange is .080 to .090 inches thick. (That's 2.032 to 2.286 mm)

A standard barrel bushing is "straight bore." The angle bored bushing is something that EGW came up with to allow for a tightly-fitted barrel bushing that still allows the barrel to swing down when it comes out of battery without "springing" (being restrained against angular rotation by the bushing holding onto the barrel)

Saulius I.
1st February 2009, 12:01
1 English inch = 25.4 mm

The standard 1911 parts are:

Barrel bushing
Recoil spring plug
Recoil spring (for a 9mm, of course)
Recoil spring guide (either standard or full-length)
Hammer (and hammer pin)
Hammer strut (and strut pin)
Sear (and sear pin)
Disconnector
Mainspring and related parts
Sear spring
Firing pin and firing pin stop (Series 80 style)
Firing pin spring
Ejector
Plungers and plunger spring (the plunger tube is integral to the frame)
Thumb safety
Grip Safety
Slide Stop

Para does not use a thick flange on the barrel bushing. A standard barrel bushing flange is .080 to .090 inches thick. (That's 2.032 to 2.286 mm)

A standard barrel bushing is "straight bore." The angle bored bushing is something that EGW came up with to allow for a tightly-fitted barrel bushing that still allows the barrel to swing down when it comes out of battery without "springing" (being restrained against angular rotation by the bushing holding onto the barrel)


Thanks for the information and operative response.
Are You sure the hammer fits
There is no disconnector at all, like on the regular 1911.
Please see the LDA hammer: http://www.m1911.org/technic32.htm
Sear is different and sear spring as well: http://www.m1911.org/technic27.htm
Grip safety appears to be different too.
I know that imperial inch is 2.54 cm, but what I wanted to explain is:
I have measured the barrel bushing
I.D.= 15,8 / 2,54 = .6220472440944188...
O.D. is 17.9 cm / 2,54 = 7.047244094488...
Barrel diameter: 14.9 cm / 2,54 = .5866614173...
When ordering EGW Custom Barrel Bushing, they ask to choose
http://egw-guns.com/store/index.php?main_page=product_info&cPath=34_26&products_id=129
EGW ask to choose:
Steel Type - Blue or stainless steel
Select Bore - .575" straight bore (This options should be selected)
Select O.D. - .699, .7015, .703, .705
Select model - Government (+) or Commander
Flange Type - .092, .125
These Numbers made me confused. What do I supose to select?
Thanks,
S.

Hawkmoon
1st February 2009, 16:10
My apologies. Your post did specify LDA, but I am accustomed to the P18.9 (single action) and my answer was based on that. You are correct, there is no disconnector (as we know it), and the hammer is proprietary to the LDA series pistols.

Saulius I.
1st February 2009, 16:15
My apologies. Your post did specify LDA, but I am accustomed to the P18.9 (single action) and my answer was based on that. You are correct, there is no disconnector (as we know it), and the hammer is proprietary to the LDA series pistols.

It's OK, thanks a lot for the information any way. I did contact EGW and simply asked them for the advise.
Kind regards,
Saulius

Hawkmoon
1st February 2009, 16:41
Out of curiosity, did you measure the barrel at the muzzle, or part of the way back? A military M1911 barrel holds a constant diameter for the full length, but Para-Ordnance barrels are slightly larger at the tip than the rest of the barrel.

Ideally (the experts tell me), you want the bushing to have a clearance of .001" to the slide, and the barrel to have a clearance of .001" to the barrel.

I just checked two Para upper assemblies I have on the bench. For a P15.40, the muzzle diameter of the barrel is .580", and the barrel diameter about an inch back is .575. The inside diameter of the slide is .701.

For a P13.45, the muzzle diameter is .579", the barrel an inch back is .575", and the slide I.D. is .703".

I think for the O.D. of the new bushing you probably want .7015". I don't know about your barrel measurement. It sounds too large. Please measure again. Your measurement is almost .007" larger than the LARGER of the two barrels I measured. I think you probably need either the .580" or the .581" bore, but your number is too much larger to attribute to tolerances.

Saulius I.
1st February 2009, 16:52
Out of curiosity, did you measure the barrel at the muzzle, or part of the way back? A military M1911 barrel holds a constant diameter for the full length, but Para-Ordnance barrels are slightly larger at the tip than the rest of the barrel.

Ideally (the experts tell me), you want the bushing to have a clearance of .001" to the slide, and the barrel to have a clearance of .001" to the barrel.

I just checked two Para upper assemblies I have on the bench. For a P15.40, the muzzle diameter of the barrel is .580", and the barrel diameter about an inch back is .575. The inside diameter of the slide is .701.

For a P13.45, the muzzle diameter is .579", the barrel an inch back is .575", and the slide I.D. is .703".

I think for the O.D. of the new bushing you probably want .7015". I don't know about your barrel measurement. It sounds too large. Please measure again. Your measurement is almost .007" larger than the LARGER of the two barrels I measured. I think you probably need either the .580" or the .581" bore, but your number is too much larger to attribute to tolerances.

I have just measured again and it is .5787, so probably I did a mistake on conversion :) Oops:)
So do You know what original 1911 parts fit to Para LDA 18.9?
Especially I'm interested in firing pin and firing pin stop size and diameter?
Appears that the slide stop is the same as for .45 double stack.
What about ambi-thumb safety?
Thanks for help.
S.

SMMAssociates
2nd February 2009, 16:35
Saulius:

Normally, you fit a barrel to a bushing, so the dimensions really don't matter as long as the original bushing dimension is very close to the barrel's....

The LDA innards (hammer, disconnector, trigger, etc., should all be the same across the LDA line. Other parts, are generally quite standard except for the mag release and maybe the slide stop. (The slide stop thing is heresay.... I have one here that I couldn't put an SA's slide stop into. OTOH, some fitting might have made it work.)

Firing pin and stop should be the same.

I'm sure there are ambi safeties for the LDA, but I'd not expect one made for an SA gun would fit. Overall, if you ignore the few variations for double-stackers, LDA guns are essentially the same as SA's, except for the specific LDA parts - mostly the lockwork. Note that the frames and slides are NOT interchangeable with SA guns.

Regards,

Saulius I.
3rd February 2009, 00:38
Saulius:

Normally, you fit a barrel to a bushing, so the dimensions really don't matter as long as the original bushing dimension is very close to the barrel's....

The LDA innards (hammer, disconnector, trigger, etc., should all be the same across the LDA line. Other parts, are generally quite standard except for the mag release and maybe the slide stop. (The slide stop thing is heresay.... I have one here that I couldn't put an SA's slide stop into. OTOH, some fitting might have made it work.)

Firing pin and stop should be the same.

I'm sure there are ambi safeties for the LDA, but I'd not expect one made for an SA gun would fit. Overall, if you ignore the few variations for double-stackers, LDA guns are essentially the same as SA's, except for the specific LDA parts - mostly the lockwork. Note that the frames and slides are NOT interchangeable with SA guns.

Regards,

Thanks for the information.
I have solved the problem with bushing, by reading FAQ on the EGW website. Everything is elxplained for newbies, that's for me. I have been shooting double stack Bul M5 iun .40S&W for few years and knew everything about it, just it had no bushing. Para LDA 18.9 has .065 firing pin (like a newer Caspian or Colt 38 Sup/10 mm). The bore diameter is .581. Outer bushing diameter is .702. Originally it has thin GI type flange and specific mag catch, which fit to double stack Para, Kimber and Bul M5. That is what I have found out so far...
Regards,
S.